SOP Title: Operation, Cleaning and Calibration of Karl Fischer Apparatus
- Objective:
To lay down the procedure for Operation, Cleaning and Calibration of Karl Fischer Apparatus.
- Scope:
This SOP is applicable for Operation, Cleaning and Calibration of Karl Fischer Apparatus located in Quality Control Laboratory.
- Responsibility:
- Quality Control: To prepare and review the SOP. To follow the procedures laid down for Operation, Cleaning and Calibration of Karl Fischer Apparatus as per this SOP.
- Engineering Department: To carry out preventive maintenance as per schedule and procedure defined.
- Quality Assurance Department: To review and approve the SOP and Annexures.
- Accountability:
Head Quality Control Department, Head Quality Assurance Department
- Procedure:
| 5.1 | Safety Precautions/Instructions: | |
| 5.1.1 | Ensure all the electrical connections are properly earthed. Ensure the power plug of the Karl Fischer Apparatus is fixed in the socket properly. | |
| 5.1.2 | Wear personal protective equipments such as safety glasses, hand gloves, nose mask during operation of instrument. | |
| 5.1.3 | Ensure that the ON/OFF switch is working properly by switching “ON” the Karl Fischer Apparatus. | |
| 5.2 | Operational Procedure: | |
| 5.2.1 | Check the validity of Calibration before starting any operations. | |
| 5.2.2 | Switch ON the mains of the instrument. | |
| 5.2.3 | ON/OFF switch is provided on the front panel. This switch puts the instrument ‘ON’ and LCD screen will glow. | |
| 5.3 | Preparing the instrument for titration: | |
| 5.3.1 | Add as per requirement K/F Reagent in the reservoir bottle fitted with the adaptor. | |
| 5.3.2 | Needless to state that the glassware used should be well dried; otherwise reagent will become useless before use. | |
| 5.3.3 | Remove the large rubber cork and add some K/F grade methanol to the reaction beaker to such an extent that the metal wires of sensors in the beaker are fully immersed. | |
| 5.3.4 | Replace the cork immediately to prevent moisture from atmosphere entering in the beaker. | |
| 5.3.5 | Connect the leads of the Pt – Sensors to the sockets provided on the instrument. | |
| 5.3.6 | Connect the titrator to mains supply and put the mains switch ‘ON’. The four line LCD display will ‘GLOW’. | |
| 5.3.7 | Adjust the speed of the magnetic stirrer such that the sensor wires do not get exposed to air. | |
| 5.3.8 | The height of the sensors in the beaker should be so adjusted that the magnetic stirrer does not hit them while rotating. | |
| 5.4.17 | This indicates that the methanol is neutralised and 1st stage of titration is over. | |
| To test the sample: | ||
| 5.4.47 | Carry out the operation as per define in operation manual. | |
| 5.4.48 | Update the “Instrument/Equipment Usage Log Book” as per SOP. | |
| 5.5 | Cleaning Procedure: | |
| 5.5.1 | Fill methanol in the second reservoir of amber colour 250 ml bottle. Lift the (glass) Adapter from the K/F Reagent bottle and attach the adapter to the methanol bottle. | |
| 5.5.2 | Press ‘CLEAN’ key; the dispensing unit will start sucking the methanol from the bottle. | |
| 5.5.3 | When clear drops from the dispensing tube start falling in the titration vessel, just detach the tube from the glass adapter. | |
| 5.5.4 | The remaining methanol in the dispensing tube will empty into the titration vessel and after few minutes the system will stop automatically. | |
| 5.5.10 | The dispensing unit will start sucking the methanol. To ‘stop’ in between, press ‘STOP’ key again. OR the system will stop automatically after few minutes. | |
| 5.5.13 | Take some acetone in a small beaker and dip the wires of the sensors in it, shake the beaker gently so that the sensors get cleaned. Wash the reaction beaker and dry it in the oven. | |
| 5.6 | Calibration Procedure: | |
| Frequency: Quarterly or after carrying out any major maintenance work. | ||
| 5.6.1 | Generate the A. R. No. on the “Instrument/Equipment Calibration Register” as per SOP and give requisition to QA department for calibration formats of instruments on the due date of calibration. | |
| 5.6.2 | For issuance of calibration report refer SOP. | |
| 5.6.3 | Perform the calibration of instrument as per Annexure and procedure mentioned below. | |
| 5.6.4 | Calibration of Karl Fischer Apparatus is performed for below parameters:
1. Water content of Sodium tartrate 2. Dispenser calibration |
|
| 1. Water content of Sodium tartrate: | ||
| 5.6.5 | Weigh about 5mg to 50mg of Sodium tartrate. Titrate with KF reagent. Note down reading in annexure. Calculate % moisture content. Operate the instrument as per SOP. | |
| 5.6.6 | Water equivalent Factor for Karl Fischer reagent is determined by using about 25mg of purified water in triplicate. | |
| 5.6.7 | Enter the details in calibration report as per Annexure. Ensure that the results obtained, comply with the acceptance criteria.
|
|
| Dispenser calibration: | ||
| 5.6.8 | Allow the dispenser to run for sometime so that the Inlet and Outlet tubes are filled with water. This can be done by running the clean cycle of the dispenser. | |
| 5.6.9 | Thus the dispenser is now ready for calibration after air bubble is removed. Now weigh the empty beaker accurately and note down its weight.
|
|
| 5.6.24 | Dispense 10mL of water in beaker from dispenser. Note down the weight of beaker with water. The same experiment is repeated thrice and the average volume is calculated. | |
| 5.6.25 | Each time calculate the dispensed volume and record in annexure. | |
| 5.6.28 | Enter the details in calibration report as per Annexure. Ensure that the results obtained, comply with the acceptance criteria. | |
| 5.6.29 | Update the “Instrument/Equipment Usage Log Book”, “Annual Calibration Schedule” and “Monthly Calibration Schedule” as per SOP. | |
| 5.6.30 | Affix the “Calibration Status Label” on the Instrument as per SOP. | |
| 5.6.31 | If calibration activity is outsourced, the values are to be transcribed in the Annexure, and external party certificate to be attached. | |
| 5.6.32 | If any breakdown occurs, follow procedure as per SOP number. | |
- Definitions /Abbreviations:
- Breakdown: Any activity leading to operation of instrument/equipment other than the set parameters or unusual sound or vibration observed in the instrument/equipment.
- Calibration: Tests performed to ensure that the instrument/equipment is functioning as per set parameters. These tests are performed as per predefined frequency and also after any major repair or replacement of parts.
- Preventive Maintenance: Maintenance activity performed to ensure that the instrument/equipment will function smoothly and to avoid breakdowns. These activities are performed as per predefined frequency.
- Abbreviations:
| Abbreviation | Expansion |
| secs | seconds |
| K/F | Karl Fischer |
| LCD | Liquid Crystal Diode |
| i.e. | That is |
| Pt. | Platinum |
| g | gram |
| Lit | Litre |
| Av. | Average |
| EX. | Extra |
| e.g. | Example |
| K.F.R. | Karl Fischer Reading |
| ml | millilitre |
| PPM | Parts Per Million |
| A.R.No. | Analytical Reference Number |
| mg | milligram |
| Conf. | Confirmation |
Calibration Report
Note: Carry out the calibration of the instrument as per SOP for the following parameters:
| Quantity of Water
Weighed W (mg) |
Burette Reading
BR (ml) |
Karl Fischer Reagent Water equivalent Factor F = W / BR |
% RSD |
Acceptance
Criteria |
|
NMT 2.0 % |
||||
Mean Factor = F =__________
| Quantity of Sodium Tartarate weighed
W1 (gms) |
Burette Reading
Y ml |
% Moisture Content
(% w/w) |
Acceptance Criteria |
| 15.35 – 15.97 %w/w |
Calculation:
% Moisture Content = Y x F x 100 = ———– w/w
W1 x 1000
Dispenser calibration:
| Parameters | Observations | Acceptance Criteria | Complies / Does Not Complies |
| Weight of the empty beaker (A) | Not more than ± 0.20 ml of volume of water taken | ||
| Required volume of water to be dispensed | |||
| Weight of the empty beaker + volume dispensed (B) | |||
| Actual volume of water dispensed (B – A)/0.99707 |
Remark: The result Complies/Does not complies as per acceptance criteria.
*Note – Ready to use SOP available in “DOWNLOAD” Section.